PPT-Parsing

Prelude Reading text thisissometextwithoutspacesandpunctuationmarkswhichist hereforequitedifficulttoreadbyhumanslexicalanalysiswillbre akthistextupintowordswhiletheparsingphasewillextractthegr. CS 4705. Julia Hirschberg. 1. Some slides adapted from Kathy McKeown and Dan Jurafsky. Syntactic Parsing. Declarative . formalisms like CFGs, FSAs define the . legal strings of a language. -- but only tell you whether a given string is legal in a particular language. -- Basic functions. Generally, an independent course, maybe plus one semester on implementation of a compiler.. High level language program .  program in assembly language or object code directly. In-domain vs out-domain. Annotated data in. Domain A. A. Parser. Training. Parsing texts in . Domain A. Parsing texts in Domain B . In-domain. Out-domain. Motivation. F. ew or no labeled resources exist for parsing text of the target domain.. Roger L. Costello. 28 September 2014. Flat XML Document. You might receive an XML document that has no structure. For example, this XML document contains a flat (linear) list of Book data:. <Books>. CSCI-GA.2590. Ralph . Grishman. NYU. Ever Faster . Change from CKY and graph-based parsers to transition-based parsers has led to large speed-ups. with little loss of performance. making full-sentence parsing viable for large corpora. Bottom-up parsing. Bottom-up parsing builds a parse tree from the leaves (terminals) to the start symbol. int. E. int. T. *. T. E. +. T. int. (4). (2). (3). (5). (1). int. *. +. int. E . . T + E | T. Excel can not only be used to process numbers, but also text.. This often . involves taking apart . (parsing) or . putting together text values (strings).. The parts into . which . we split a string will be called . Top-down vs. bottom-up parsing. Top-down . vs. bottom-up . parsing. Ex. Ex. Ex. Ex. +. Nat. *. Nat. Nat. Ex. Ex. . . . Nat. | . (. Ex. ). | . Ex. . +. . Ex. | . Ex. . *. . Ex. Matched input string. Alexander Fraser & Liane Guillou. {fraser,liane}@cis.uni-muenchen.de. CIS. , . Ludwig-Maximilians-Universität München. Computational . Morphology and Electronic Dictionaries. SoSe 2016. 2016-05-09. 1. Some slides . adapted from Julia Hirschberg and Dan . Jurafsky. To view past videos:. http://. globe.cvn.columbia.edu:8080/oncampus.php?c=133ae14752e27fde909fdbd64c06b337. Usually available only for 1 week. Right now, available for all previous lectures. Top-down versus Bottom-up Parsing. Top down:. Recursive descent parsing. LL(k) parsing. Top to down and leftmost derivation . Expanding from starting symbol (top) to gradually derive the input string. Semantic Parsing. Converting natural language to a logical form. e.g., executable code for a specific application. Example:. Airline reservations. Geographical query systems. Stages of Semantic . Parsing. Parsing Giuseppe Attardi Dipartimento di Informatica Università di Pisa Università di Pisa Question Answering at TREC Consists of answering a set of 500 fact-based questions, e.g. “When was Mozart born Parsing Giuseppe Attardi Dipartimento di Informatica Università di Pisa Università di Pisa Question Answering at TREC Consists of answering a set of 500 fact-based questions, e.g. “When was Mozart born